1. Field of the Invention
The invention relates to a method and apparatus for location identification and positioning. In particular, the invention relates to a method, apparatus, and system for determining the position of an RFID reading device when it moves around within a region based on reading patterns of the RFID tags dispersed throughout the region.
2. Description of Related Art
Positioning and location identification information is useful in a number of industrial fields. In logistics and transportation domain, for example, the capability to identify the position of each cargo, carrier, vehicle, and even human in real-time provides visibility to the whole supply chain.
Global Positioning System (“GPS”) has frequently been used to determine the position of a user around the globe. However, a GPS receiver requires a good view of the sky at all times. When it comes to indoor applications, GPS is not reliable solution due to the poor reception of satellite signals. In addition, for in-house applications, the required precision, sometimes as high as within one meter, is higher than that of the outdoor applications. GPS apparatus with higher precision comes at a higher price. Therefore, using precise GPS for local in-house positioning is not an economical solution.
Most of the existing Indoor Positioning Systems (“IPS”) are based on Wireless Local Area Network (“WLAN”) for which wireless access points are installed in each room and a portable receiving device can determine which room the device is in when it receives signals from installed access points. However the precision of this type of systems is not high enough for logistics applications. Furthermore, there will be problems if any of the access points fails to work.
Within a warehouse, a cargo terminal, or a truck depot, it is often desirable to know the position of each vehicle, and to give it the correct instruction for picking up or dropping off cargos at a certain location. Incorrect instructions and misplacements could be very costly, leading to wrong delivery, inadequate supply, customer dissatisfaction, and finally lost revenues. Thus there is a need for a robust method, system and apparatus for precise indoor positioning at a reasonable cost.